[unreadable] Heart disease is the leading cause of death in the United States today. New studies are showing that cardiac motion analysis using magnetic resonance (MR) imaging can be a sensitive indicator of functional abnormalities in the heart. Although new, fast two-dimensional, MR imaging protocols enable real-time acquisition of both anatomical and strain images, these protocols do not provide dense, three-dimensional (3D), reproducible functional strain measures throughout the entire ventricular system including the right ventricle and throughout the entire cardiac cycle including diastole. The harmonic phase (HARP) MR imaging approach has been shown to be a flexible, accurate, and robust approach that exploits the concept of MR tagging and communications theory to compute a variety of heart muscle motion quantities, including the tracking of points, Eulerian and Lagrangian strain, direction of maximum thickening, and ejection fraction. [unreadable] [unreadable] The goals of the proposed research are to further develop and validate the HARP MR imaging method in 3D, which we believe will make detailed analysis of both ventricles throughout the cardiac cycle clinically feasible in heart failure patients. Specifically, we propose to 1) optimize HARP reconstruction methods; 2) develop, implement, and test 3D HARP imaging methods on an MR scanner; 3) develop, implement, and test 3D HARP image processing and analysis methods; and 4) validate 3D HARP methods in phantoms, normal volunteers, and heart failure patients. In this research, we will push the MR tagging technology further, leading to novel 3D ventricular imaging protocols, enabling fast imaging and automatic and reproducible 3rocessing that has heretofore not been possible. Through the joint development of fast 3D MR imaging -methods and computer analysis methods, there is strong potential for this approach to lead to an effective clinical protocol for the evaluation of regional myocardial function in health and disease. [unreadable] [unreadable]